1. Field of the Invention
The invention relates to a process in which both hydrocarbons and hydrogen are produced from syngas. More particularly, the invention relates to a gas conversion process for synthesizing hydrocarbons and producing hydrogen from syngas, with the hydrogen used for at least one of (i) hydrocarbon synthesis catalyst rejuvenation and (ii) hydrocarbon product upgrading.
2. Background of the Invention
Hydrocarbon synthesis processes are known in which a synthesis gas feed comprising a mixture of H.sub.2 and CO is fed into a hydrocarbon synthesis reactor in which it reacts in the presence of a Fischer-Tropsch catalyst under conditions effective to form higher molecular weight hydrocarbons. These processes include fixed bed, fluid bed and slurry hydrocarbon synthesis, all of which are well documented in various technical articles and in patents. In many cases it is desired that the synthesized hydrocarbons comprise mostly C.sub.5+ hydrocarbons (e.g., C.sub.5+ -C.sub.200) and preferably C.sub.10+ hydrocarbons, at least a portion of which are solid at standard conditions of room temperature and pressure. It is preferred in a slurry hydrocarbon synthesis process that the hydrocarbons comprise mostly C.sub.5+ paraffins. These hydrocarbons are upgraded to more valuable products by one or more hydroconversion operations in which at least a portion of the molecular structure is changed by reacting with hydrogen. Hydroconversion operations therefore all require hydrogen. Hydrogen is also required for rejuvenating the hydrocarbon synthesis catalyst and sometimes for maintaining or changing the H.sub.2 to CO ratio of the syngas feed for the hydrocarbon synthesis. It is desirable to have a hydrocarbon synthesis process which generates the hydrogen required for the hydrocarbon synthesis catalyst rejuvenation and also for the hydroconversion upgrading of the synthesized hydrocarbons, rather than depending on an outside source of hydrogen.